Package org.apache.lucene.store

Class FilterIndexInput

java.lang.Object

org.apache.lucene.store.DataInput

org.apache.lucene.store.IndexInput

org.apache.lucene.store.FilterIndexInput

All Implemented Interfaces:

Closeable, AutoCloseable, Cloneable

public class FilterIndexInput
extends IndexInput

IndexInput implementation that delegates calls to another directory. This class can be used to add limitations on top of an existing IndexInput implementation or to add additional sanity checks for tests. However, if you plan to write your own IndexInput implementation, you should consider extending directly IndexInput or DataInput rather than try to reuse functionality of existing IndexInputs by extending this class.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Field Summary

Fields

Modifier and Type	Field	Description
protected IndexInput	in

Constructor Summary

Constructors

Constructor	Description
FilterIndexInput(String resourceDescription, IndexInput in)	Creates a FilterIndexInput with a resource description and wrapped delegate IndexInput

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the stream to further operations.
IndexInput	getDelegate()	Gets the delegate that was passed in on creation
long	getFilePointer()	Returns the current position in this file, where the next read will occur.
long	length()	The number of bytes in the file.
byte	readByte()	Reads and returns a single byte.
void	readBytes(byte[] b, int offset, int len)	Reads a specified number of bytes into an array at the specified offset.
void	seek(long pos)	Sets current position in this file, where the next read will occur.
IndexInput	slice(String sliceDescription, long offset, long length)	Creates a slice of this index input, with the given description, offset, and length.
static IndexInput	unwrap(IndexInput in)	Unwraps all FilterIndexInputs until the first non-FilterIndexInput IndexInput instance and returns it

Methods inherited from class org.apache.lucene.store.IndexInput

clone, getFullSliceDescription, randomAccessSlice, skipBytes, toString

Methods inherited from class org.apache.lucene.store.DataInput

readBytes, readFloats, readGroupVInt, readGroupVInts, readInt, readInts, readLong, readLongs, readMapOfStrings, readSetOfStrings, readShort, readString, readVInt, readVLong, readZInt, readZLong

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

in

protected final IndexInput in

Constructor Detail

FilterIndexInput

public FilterIndexInput(String resourceDescription,
                        IndexInput in)

Creates a FilterIndexInput with a resource description and wrapped delegate IndexInput

Method Detail

unwrap

public static IndexInput unwrap(IndexInput in)

Unwraps all FilterIndexInputs until the first non-FilterIndexInput IndexInput instance and returns it

getDelegate

public IndexInput getDelegate()

Gets the delegate that was passed in on creation

close

public void close()
           throws IOException

Description copied from class: IndexInput

Closes the stream to further operations.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in class IndexInput

Throws:

IOException

getFilePointer

public long getFilePointer()

Description copied from class: IndexInput

Returns the current position in this file, where the next read will occur.

Specified by:

getFilePointer in class IndexInput

See Also:

IndexInput.seek(long)

seek

public void seek(long pos)
          throws IOException

Description copied from class: IndexInput

Sets current position in this file, where the next read will occur. If this is beyond the end of the file then this will throw EOFException and then the stream is in an undetermined state.

Specified by:

seek in class IndexInput

Throws:

IOException

See Also:

IndexInput.getFilePointer()

length

public long length()

Description copied from class: IndexInput

The number of bytes in the file.

Specified by:

length in class IndexInput

slice

public IndexInput slice(String sliceDescription,
                        long offset,
                        long length)
                 throws IOException

Description copied from class: IndexInput

Creates a slice of this index input, with the given description, offset, and length. The slice is sought to the beginning.

Specified by:

slice in class IndexInput

Throws:

IOException

readByte

public byte readByte()
              throws IOException

Description copied from class: DataInput

Reads and returns a single byte.

Specified by:

readByte in class DataInput

Throws:

IOException

See Also:

DataOutput.writeByte(byte)

readBytes

public void readBytes(byte[] b,
                      int offset,
                      int len)
               throws IOException

Description copied from class: DataInput

Reads a specified number of bytes into an array at the specified offset.

Specified by:

readBytes in class DataInput

Parameters:

b - the array to read bytes into

offset - the offset in the array to start storing bytes

len - the number of bytes to read

Throws:

IOException

See Also:

DataOutput.writeBytes(byte[],int)